Merge branch 'topic/axi' into for-linus (049d0d38) · Commits · e / devices / android_kernel_teracube_emerald

drivers/dma/dma-axi-dmac.c

+55 −20

Original line number	Diff line number	Diff line
		@@ -72,6 +72,9 @@

		#define AXI_DMAC_FLAG_CYCLIC BIT(0)

		/* The maximum ID allocated by the hardware is 31 */
		#define AXI_DMAC_SG_UNUSED 32U

		struct axi_dmac_sg {
		dma_addr_t src_addr;
		dma_addr_t dest_addr;
		@@ -80,6 +83,7 @@ struct axi_dmac_sg {
		unsigned int dest_stride;
		unsigned int src_stride;
		unsigned int id;
		bool schedule_when_free;
		};

		struct axi_dmac_desc {
		@@ -200,11 +204,21 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)
		}
		sg = &desc->sg[desc->num_submitted];

		/* Already queued in cyclic mode. Wait for it to finish */
		if (sg->id != AXI_DMAC_SG_UNUSED) {
		sg->schedule_when_free = true;
		return;
		}

		desc->num_submitted++;
		if (desc->num_submitted == desc->num_sgs)
		chan->next_desc = NULL;
		if (desc->num_submitted == desc->num_sgs) {
		if (desc->cyclic)
		desc->num_submitted = 0; /* Start again */
		else
		chan->next_desc = NULL;
		} else {
		chan->next_desc = desc;
		}

		sg->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID);

		@@ -220,9 +234,11 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan)

		/*
		* If the hardware supports cyclic transfers and there is no callback to
		* call, enable hw cyclic mode to avoid unnecessary interrupts.
		* call and only a single segment, enable hw cyclic mode to avoid
		* unnecessary interrupts.
		*/
		if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback)
		if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback &&
		desc->num_sgs == 1)
		flags \|= AXI_DMAC_FLAG_CYCLIC;

		axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1);
		@@ -237,37 +253,52 @@ static struct axi_dmac_desc axi_dmac_active_desc(struct axi_dmac_chan chan)
		struct axi_dmac_desc, vdesc.node);
		}

		static void axi_dmac_transfer_done(struct axi_dmac_chan *chan,
		static bool axi_dmac_transfer_done(struct axi_dmac_chan *chan,
		unsigned int completed_transfers)
		{
		struct axi_dmac_desc *active;
		struct axi_dmac_sg *sg;
		bool start_next = false;

		active = axi_dmac_active_desc(chan);
		if (!active)
		return;
		return false;

		if (active->cyclic) {
		vchan_cyclic_callback(&active->vdesc);
		} else {
		do {
		sg = &active->sg[active->num_completed];
		if (sg->id == AXI_DMAC_SG_UNUSED) /* Not yet submitted */
		break;
		if (!(BIT(sg->id) & completed_transfers))
		break;
		active->num_completed++;
		sg->id = AXI_DMAC_SG_UNUSED;
		if (sg->schedule_when_free) {
		sg->schedule_when_free = false;
		start_next = true;
		}

		if (active->cyclic)
		vchan_cyclic_callback(&active->vdesc);

		if (active->num_completed == active->num_sgs) {
		if (active->cyclic) {
		active->num_completed = 0; /* wrap around */
		} else {
		list_del(&active->vdesc.node);
		vchan_cookie_complete(&active->vdesc);
		active = axi_dmac_active_desc(chan);
		}
		} while (active);
		}
		} while (active);

		return start_next;
		}

		static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
		{
		struct axi_dmac *dmac = devid;
		unsigned int pending;
		bool start_next = false;

		pending = axi_dmac_read(dmac, AXI_DMAC_REG_IRQ_PENDING);
		if (!pending)
		@@ -281,10 +312,10 @@ static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid)
		unsigned int completed;

		completed = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE);
		axi_dmac_transfer_done(&dmac->chan, completed);
		start_next = axi_dmac_transfer_done(&dmac->chan, completed);
		}
		/* Space has become available in the descriptor queue */
		if (pending & AXI_DMAC_IRQ_SOT)
		if ((pending & AXI_DMAC_IRQ_SOT) \|\| start_next)
		axi_dmac_start_transfer(&dmac->chan);
		spin_unlock(&dmac->chan.vchan.lock);

		@@ -334,12 +365,16 @@ static void axi_dmac_issue_pending(struct dma_chan *c)
		static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs)
		{
		struct axi_dmac_desc *desc;
		unsigned int i;

		desc = kzalloc(sizeof(struct axi_dmac_desc) +
		sizeof(struct axi_dmac_sg) * num_sgs, GFP_NOWAIT);
		if (!desc)
		return NULL;

		for (i = 0; i < num_sgs; i++)
		desc->sg[i].id = AXI_DMAC_SG_UNUSED;

		desc->num_sgs = num_sgs;

		return desc;